This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Human amnion epithelial cells (hAEC) have attracted a lot of attention as a cell source for regenerative therapies. X-ray tomography will allow us to shed light on the the process of differentiation of hAECs cells. We propose to use X-ray tomography in the water window energy range in combination with immunegold labelling of the cellular cytoskeleton, and organelles such as mitochondria, which will enable high spatial resolution imaging of fine-scale structural changes in the cells during the differentiation process of the hAECs towards functional lung epithelial cell phenotypes.